DENVER — Denver doctor Justin Neisler, 31, pleaded guilty to producing child pornography Thursday.

Investigators allege Neisler secretly filmed young male patients while they were naked and uploaded child pornography to the social media site Tumblr.

U.S. Attorney for the District of Colorado Jason Dunn said Friday that Neisler uploaded the pornographic material between Oct. 15, 2018 and Dec. 13, 2018.

Neisler was arrested in March 2019. 

During a search of his Cherry Creek apartment, authorities determined Neisler “kept child pornography on his cell phone and on various other electronic media.”

A forensic review by the Federal Bureau of Investigation revealed Neisler’s devices had about 6,600 still images and 1,725 videos of child pornography that he had obtained from the internet, according to the U.S. Attorney’s Office.

According to Centura Health, Neisler worked at the Family Residency Program at St. Anthony North Family Medicine 84th Clinic in Westminster. Centura said Neisler was terminated when the company learned of his arrest.

Investigators say they found Neisler secretly recorded patients using a Spy Pen Camera and his iPhone.

“He would then watch those videos at home for his own sexual gratification.  As part of investigating and prosecuting this case, minor victims have been identified and interviewed to make certain that no other hands-on offenses occurred, and that those victims’ needs are addressed, and that the videos of those victims have not been distributed,” the U.S. Attorney’s Office said.

Neisler faces between 15 and 30 years in prison.

His sentencing is scheduled for May 22.